Disc blade sharpener

ABSTRACT

A disc blade sharpener. A wheel carriage includes a rotatable abrasive wheel contactable against the side surface of the cutting edge of the disc blade. A rotatable driver wheel mounted on the carriage rotates the disc blade while the abrasive wheel contacts and sharpens the cutting edge of the disc blade. The carnage includes an electric motor, abrasive wheel, and driver wheel that may be adjustably moved both in a horizontal direction and a vertical direction relative to the concave disc blade.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relate, generally to the field of sharpening devices, and more specifically those used for sharpening disc blades.

2. Description of the Prior Art

Soil cultivators a include a plurality of discs rotatably driven to engage and cultivate the ground. The blades may take different shapes. For example, in FIG. 1 there is shown a plurality of concave discs 10 fixedly mounted upon a rotatably driven axle 11, in turn, mounted to an agricultural vehicle. Typically, a plurality of discs are arranged so that the concave surfaces face a single direction such as discs 12 and 13 with a second plurality of discs 14 and 15 mounted on the same axle only having concave surfaces facing the opposite direction. The cutting edge 16 of each disc extends circumferentially around the disc and is located at the outer most point. As the disc engages the ground, the cutting edge will eventually become dull thereby requiring either that the disc be replaced or resharpened. By providing a sharp disc cutting edge, the disc can penetrate the ground deeper and will provide a truer cutting action. Due to the concave configuration of the disc, it is difficult to easily and quickly sharpen the cutting edge. What is needed is a device usable in the field that may be moved adjacent to the plurality of the discs and used to sharpen each disc. Disclosed herein is such a device.

SUMMARY OF THE INVENTION

One embodiment of the present invention is a sharpener for engaging and sharpening a disc blade with the disc blade mounted on and rotatably by a shaft of an implement resting atop a supporting surface. A frame has a longitudinal axis and a support upon which the frame is movable across the supporting surface to and from the disc blade. The frame further has a handle to grasp and direct the frame across the supporting surface in the direction of the axis. A power source is mounted on the frame and has a rotatable output. A driver wheel is mounted on the frame and is rotatably driven by the output to rotate the disc blade. An abrasive wheel is rotatably mounted on the frame and rotatably driven by the output against the disc blade for sharpening thereof.

It is an object of the present invention to provide a new and improved disc blade sharpener.

A further object of the present invention is to provide a disc blade sharpener that may be used to sharpen a plurality of concave disc blades facing one direction and a plurality of concave disc blades facing an opposite direction.

Related objects and advantages of the present invention will be apparent from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary cross sectional view of prior art disc blades for cultivating soil.

FIG. 2 is a fragmentary top, side perspective view of the disc blade sharpener incorporating the present invention.

FIG. 3 is a top, end perspective view.

FIG. 4 is a fragmentary, enlarged cross sectional view taken along the line 4-4 of FIG. 3 and viewed in the direction of the arrow.

FIG. 5 is a top perspective view of the end of the disc blade sharpener opposite of that shown in FIG. 3.

FIG. 6 is an enlarged fragmentary view of the drive wheel and abrasive wheel contacting and sharpening a disc.

DESCRIPTION OF THE PREFERRED EMBODIMENT

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

A disc blade sharpener 17 (FIG. 3) includes a pair of wheels 20 and 21 rotatably mounted to the upward tuned arms 23 and 24 of tube 22. An outer tube 25 is slidably mounted to tube 22 and extends around tube 22 being movable from left to right as viewed in FIG. 3 upon tube 22. A pair of bars 26 and 27 are fixedly mounted to tube 25 in cantilever fashion and extend rearwardly towards handle 28. The longitudinal axis 9 is inclined upwardly from wheels 20 and 21 to handle 28.

A carriage 30 (FIGS. 2 and 3), is slidably mounted to the rearwardly extending bars 26 and 27 with the carriage having an electric motor 7 and abrasive wheel 34 and a driver roller 35 mounted thereon. Carriage 30 is movable to and from the front wheels 20 and 21 carrying the motor, abrasive wheel and driver wheel. Suitable electrical cords 92 are provided on the frame of the sharpener to connect the motor to a source of electrical energy.

The carriage includes a pair of tubes 31 and 32 (FIG. 4) fixedly mounted to carriage plate 33. Tubes 31 and 32 enclose respectively bars 26 and 27 and slidably ride thereon.

Electric motor 7 includes a downwardly extending right angle bracket 36 having a distal end 37 mounted atop a pair of vibration isolators 38 and 29. A pair of conventional fastening devices 40 and 41 extend through plate 33, isolators 38 and 29 and distal portion 37 of bracket 36 thereby mounting the electric motor to carriage plate 33. The vibration isolators may be produced from any suitable vibration isolating material such as rubber or plastic. Fastening devices 40 and 41 may take the form of bolts and mating internally threaded nuts.

The rotatable output shaft 38 of electric motor 7 has a distal end portion having a disc shaped abrasive wheel 34 fixedly mounted thereon in conventional manner. Electric cord 92 is connected to motor 33 and has an input plug mounted to the end of the sharpener 17.

A protective shield 42 mounted to plate 33 extends partially around abrasive wheel 34 and includes a sidewall having a conventional bearing 43 mounted thereto through which axle 38 extends. Abrasive wheel 34 extends outwardly of shield 42 so that the side cutting surfaces 44 and 45 are available to contact and sharpen the concave disc blades of FIG. 1. The circumferential edge 39 of wheel 34 projects out of shield 42.

Disc shaped drive roller 35 is wheel shaped and mounted to axle 46 (FIG. 3), in turn, rotatably mounted to a hollow axle casing 47 fixedly mounted atop a pair of downwardly extending legs 48 and 49 having their opposite ends fixedly attached to plate 33. A plate 50 is mounted to legs 48 and 49 ensuring legs 48 and 49 are kept parallel. Drive roller 35 has an axis of rotation parallel to the axis of rotation of abrasive wheel 34 with the side abrasive surfaces 44 and 45 being perpendicular to both axes.

A cross member 52 is fixedly fastened to and extends between tubes 31 and 32 (FIG. 2) and includes a carriage nut 53 through which rotatable shaft 54 extend. Shaft 54 extends beneath plate 50. The end of shaft 54 closest to handle 28 (FIG. 5) extends through cross tube 55 and has a crank 56 secured thereto. By rotating crank 56, shaft 54 is caused to rotate thereby moving cross member 52 and carriage 30 (FIG. 2) to and from wheels 20 and 21.

Bars 27 and 26 (FIG. 5) have opposite ends fixedly attached to plate 60 and to cross member 55. Further, a plate 61 is fixedly mounted to the bars and extends downwardly having a pair of outwardly extending legs 62 and 63 to support in conjunction with wheels 20 and 21 the apparatus atop ground or other supporting surface. Handle 28 includes a pair of right angle arms 64 and 65 having respectively inwardly turned ends 66 and 67 slidable mounted to tube 55. Ends 66 and 67 have an outside configuration complementary to the inside configuration of tube 55. In the embodiment shown in FIG. 5, ends 66 and 67 have a square cross section slightly smaller than the interior square cross section of tube 55. A pair of removable pins 68 and 69 extend through tube 55 and through ends 66 and 67. In the configuration shown in FIG. 5, arm 64 and 65 extend upwardly; however, the arms may be removed from tube 55 by first removing pins 68 and 69. Arms 64 and 65 may then be positioned to extend horizontally generally with ends 66 and 67 then being reinserted into tube 55 and pins 68 and 69 inserted through tube 55 and ends 66 and 67 thereby allowing arms 64 and 65 to be grasped thereby pivoting the apparatus on wheels 20 and 21 and allowing the apparatus to be wheeled in wheelbarrow fashion towards and away from the concave disc blades shown in FIG. 1.

Belt cover 73 (FIG. 2) is fragmented in area 72 to illustrate the positioning of a pulley wheel 70 fixedly mounted to axle 46 upon which the drive roller 35 (FIG. 3) is mounted. A continuous belt 71 extends around pulley wheel 70 and a similar pulley wheel mounted to the output shaft 38 (FIG. 4) enclosed within the cover. Thus, rotation of output shaft 38 results in movement of belt 71 and pulley wheel 70 thereby causing drive roller 35 to rotate.

External tube 25 (FIG. 3) slides back and forth between wheels 20 and 21. Tube 25 has an extension 82 extending at a right angle from tube 25 rearwardly toward handle 28 and then outwardly having a distal end 83 pivotally mounted to side lever 80. Lever 80 has a first end 81 pivotally mounted by pin 84 to the interior axle tube 22 upon which wheels 20 and 21 are mounted. The opposite end 85 of lever 80 is controllably movable across a horizontally extending plate 87. End 85 is provided with an upwardly extending handle 86 allowing handle 86 to be grasped and moved horizontally pivoting lever 80 about end 83 and thereby causing tube 25 and the attached carriage 30 including bars 26 and 27 to slidably move on tube 22. For example, by moving handle 86 to the right as viewed in FIG. 3, tube 25 and the attached carriage 30 is caused to move toward wheel 21. Likewise, by moving handle 86 to the left as viewed in FIG. 3, tube 25 and the attached carriage 30 is caused to move toward wheel 20. Horizontally extending plate 87 (FIG. 5) is fixedly mounted to bar 27 and has a plurality of apertures 88 through which a downwardly extending pin mounted to the distal end of lever 80 is positioned thereby holding the lever in pace until the lever is moved slightly upward and then pivoted about end 81.

The procedure for sharpening the concave disc blade 14 of FIG. 1 with the disc blade sharpener shown in FIGS. 2-6 is to first lift handle 28 upwardly thereby pivoting the sharpener upon wheels 20 and 21. The sharpener is then moved forwardly until drive roller 35 contacts the circumferentially extending edge 16 (FIG. 6) of the blade. Handle 86 is then pulled upwardly and lever 80 is pivoted about pin 84 thereby sliding tube 25 and the attached carriage 30 sideways until the abrasive side surface 44 (FIG. 6) contacts the inside surface 92 of the cutting edge 16 of the blade. Abrasive wheel 34 is movable laterally or perpendicular to axis 9. Drive roller 35 has sufficient width to maintain contact with edge 16 even though drive wheel 35 and abrasive wheel 34 are moved laterally relative to the disc blade. Drive wheel 35 is mounted to axle 46 and includes a collar 93 surrounding the axle. A set screw 94 is provided to lock the drive roller relative to axle 46. Fastener 94 may be loosened in order to position wheel 35 on the axle relative to edge 16 while abrasive side surface 44 is in contact with surface 92. In the event the sharpener is being used to sharpen the concave discs 12 or 13 having a concave surface facing opposite of discs 14 and 16, then fastener 94 is loosened to move wheel 35 to the left as viewed in FIG. 6 so that abrasive side surface 45 may contact the concave surface 92 of the cutting edge disc 12 or 13 while the drive roller is in contact with the disc. Alignment plate 89 (FIG. 5) is mounted to belt cover 73 and is positioned adjacent drive wheel 35, A pair of indents 89 and 90 are provided in plate 89 to facilitate aligning wheel 35 on axle 46 depending on whether abrasive surface 44 or 45 is to be used.

Activation of motor 7 results in rotation of the output shaft 38 thereby causing belt 71 to rotate sprocket 70 causing axle 46 to rotate in the direction of arrow 90 along with drive wheel 35, in turn, causing rotation of disc 14 in the direction of arrow 96. With the disc rotating, final adjustment via lever 80 may be made to position abrasive side surface 44 in contact with edge concave surface 92 thereby causing edge 16 to be ground and sharpened. As the output shaft of motor 33 rotates, axle 38 will rotate in the direction of arrow 97 which is in the same direction 90 as axle 46.

Prior to contacting the abrasive side surface of abrasive wheel 34 with disc 14, it may be necessary to position the vertical height of abrasive wheel 34 relative to the disc. Bars 26 and 27 (FIG. 2) extend downwardly from handle 28 toward wheels 20 and 21. Thus, when crank 56 (FIG. 5) is rotated causing rotation of shaft 54, the carriage and mounted abrasive wheel 34 will be caused to move upwardly or downwardly depending upon the rotational direction of shaft 54. The abrasive wheel 34 is positioned so that the abrasive side surface 44 or 45 is correctly located in the vertical direction relative to the disc blade. For example, in the event disc 14 is at a relative high distance from the ground, then crank 56 is rotated so abrasive wheel 34 is moved upwardly whereas if the concave disc blade is located relatively low to the ground, then crank 56 is rotated in an opposite direction moving abrasive wheel 34 closer to wheels 20 and 21 and thereby decreasing the vertical height of the abrasive wheel relative to the ground.

The method of sharpening a disc blade having a side surface and a circumferentially extending cutting edge with the disc blade mounted on a rotatably shaft includes providing a sharpening device having a frame, an abrasive wheel rotatably mounted on the frame, and a wheel-shaped engager rotatably mounted on the frame. The sharpening device is moved toward the disc blade until the engager contacts the disc blade with the engager being rotated thereby rotating the disc blade. The abrasive wheel is moved laterally against a side surface of the disc blade and rotated while in contact with the side surface thereby sharpening the cutting edge of the disc blade. The abrasive wheel may be moved vertically on the frame and relative to the disc blade.

While the invention has keen illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. 

1. A sharpener for engaging and sharpening a disc blade having a cutting edge with the disc blade mounted on and rotatably by a shaft of an implement resting atop a supporting surface comprising: a frame with a longitudinal axis and having a support upon which said frame is movable across a supporting surface to and from an implement having a disc blade, said frame further having a handle to grasp and direct said frame across the supporting surface in the direction of said axis; a power source mounted on said frame and having a rotatable output; a driver wheel mounted on said frame and rotatably driven by said output to rotate said disc blade; and, an abrasive wheel rotatably mounted on said frame and rotatably driven by said output against said disc blade for sharpening thereof.
 2. The sharpener of claim 1 and further comprising: a carriage mounted to said frame and connected with said abrasive wheel to move said abrasive wheel laterally relative to said longitudinal axis and independent of movement of said frame to contact laterally said disc blade.
 3. The sharpener of claim 2 wherein said abrasive wheel is rotatably driven to cause relative motion between said abrasive wheel and said disc blade sharpening the edge of the disc blade.
 4. The sharpener of claim 1 and further comprising: an adjustment structure mounted to said frame and connected with said abrasive wheel to move said abrasive wheel vertically independent of movement of said frame positioning said abrasive wheel vertically relative to said disc blade.
 5. The sharpener of claim 1 wherein said handle is pivotably mounted to said frame to allow said handle to be lifted upwardly pivoting said frame on said support and move the sharpener in wheelbarrow fashion to and from the implement.
 6. The sharpener of claim 1 wherein said abrasive wheel has a first axis of rotation and said driver wheel has a second axis of rotation parallel to said first axis, said abrasive wheel includes a side abrasive surface perpendicular to said first axis with said abrasive surface movable against said disc blade to sharpen the cutting edge of the disc blade.
 7. The sharpener of claim 6 and further comprising: a carriage mounted to said frame and connected with said abrasive wheel to move said abrasive wheel laterally relative to said longitudinal axis and independent of movement of said frame to contact laterally said disc blade with said driver wheel contacting and rotating said disc blade; and wherein said handle is pivotably mounted to said frame to allow said handle to be lifted upwardly pivoting said frame on said support and move the sharpener in wheelbarrow fashion to and from the implement.
 8. A sharpener for a concave disc blade provided on an agriculture implement wherein the disc blade is rotatable driven on a shaft and has a concave side surface and a circumferentially extending cutting edge with an edge side surface comprising: a frame having a longitudinally extending axis and a supporting foot; power means having rotating output means; an engager mounted to said frame that is rotatably driven and connected to said power means to rotate the disc blade when the frame is moved into engagement with the agriculture implement having the disc blade mounted thereon; and, an abrasive wheel mounted to said frame and rotatably driven and connected to said power means, said wheel having an abrasive side surface laterally movable against and edge side surface of the disc blade to sharpen the cutting edge of the disc blade.
 9. The sharpener of claim 8 wherein: said engager is wheel-shaped and is contactingly engageable with the disc blade, said engager is rotatably by said power means to cause rotation of the disc blade when said frame is moved to contact the disc blade.
 10. The sharpener of claim 9 wherein: said abrasive wheel is movable sideways generally perpendicular to said longitudinally extending axis of the frame to contact the abrasive side surface at the location of the cutting edge to sharpen same.
 11. The sharpener of claim 10 and her comprising: a first locating mechanism movably mounted to said frame and connected to said abrasive wheel to move said abrasive wheel vertically relative to the disc blade.
 12. The sharpener of claim 11 and further comprising: a second locating mechanism movably mounted to said frame and connected to said abrasive wheel to move said abrasive wheel laterally and perpendicular to said longitudinal axis to and from the disc blade.
 13. A method of sharpening a disc blade having a side surface and a circumferentially extending cutting edge with the disc blade mounted on a rotatably driven shaft comprising the steps off: providing a sharpening device having a frame, an abrasive wheel rotatably mounted on said frame, and a wheel-shaped engager rotatably mounted on said frame; moving said sharpening device toward a disc blade mounted on a rotatable shaft; rotating said wheel-shaped engager to rotate said disc blade; moving said abrasive wheel laterally against a side surface of the disc blade; and, rotating said abrasive wheel while said abrasive wheel is in contact with said side surface sharpening the cutting edge of the disc blade.
 14. The method of sharpening a disc blade of claim 13 and comprising the additional step of: moving said abrasive wheel vertically on said frame to move said abrasive vertically relative to said disc blade. 